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EC number: 257-406-8
CAS number: 51772-35-1
The test item is not bioaccumulative according to PBT criteria.
bioaccumulation potential of the substance was assessed in a weight of
evidence approach using several QSAR calculations as well as one
only available experimental result is a BCF study conducted in 1984
(Gakashuin University 1984). The study was conducted according to
"Bioconcentration test for chemical substances in fishery products in
accordance with Notification of Kanpogyo No. 5, Yakuhatsu No. 615,
Kikyoku No. 49-392". For test substance preparation an emulsifier
was used. The tested concentrations of the substance were 0.1 and 1
mg/L, respectively, and it resulted in BCF values of 13.6 - 13.8 (1 mg/L
test concentration) and 14 - 19 (0.1 mg/L test concentration). Because
the tested concentrations are far above the actual water solubility of
the substance (< 0.0017 mg/L) and the additional use of a solubilizer in
substance preparation the study cannot be regarded as valid. However, in
a weight of evidence approach the results give additional information
about the degree of bioaccumulation.
QSAR models have been used to properly assess the bioaccumulation
potential in a weight-of-evidence approach. The single models and their
results are summarized in the table below:
all mitigating factors applied; 96 % in domain
Arnot-Gobas upper trophic level
Including biotransformation rate estimates
Arnot-Gobas mid trophic level
Arnot-Gobas lower trophic level
general, the QSAR models only taking into account the logKow of the
substance are hardly applicable (e.g. EPISuite regression-based
estimate)because the partition coefficient of the substance is in a
range were the linearity between logKow and log BCF is decreasing and
therefore the obtained results are of low value.
the results of the model calculation, the calculated BCF values range
from 209.41 (Catalogic) to 3321 (EPISuite v4.10, regression-based
estimate). Of these models, Catalogic, VEGA CAESAR and the Arnot-Gobas
model from EPISuite v4.10 take into account mitigating factors, e.g.
metabolism, water solubility and/or size. Catalogic revealed a corrected
BCF of 209.41 and the compound is 96% within the model’s applicability
domain. . The Arnot-Gobas model from the EPISuite takes into account the
biotransformation rate of the compound and calculates BCF values for the
upper, mid and lower trophic levels. The values for the present compound
range from 452.9 (upper trophic level) to 706.9 (lower trophic level).
The model assumes default lipid contents of 10.7%, 6.85% and 5.98% for
the upper, middle and lower trophic levels, respectively. Usually, in
the context of REACH a default lipid value of 5% is assumed which
represents the average lipid content of the small fish used in OECD 305
studies. Thus, the higher lipid values of the Arnot-Gobas model can be
regarded as reasonable worst-case scenarios as higher lipid contents are
usually associated with a higher potential for bioaccumulation.
regression-based estimate from the EPISuite revealed a BCF value of 3321
based on a calculated logKow of 8.23. This model correlates the logBCF
to the logKow. According to ECHA’s guidance on information requirements
and chemical safety assessment, chapter R.11: PBT assessment,
logBCF increases linearly with logKow which is the basis for the “B”
screening criterion of logKow > 4.5. However, at very high logKow (> 6),
a decreasing relationship between the two parameters is observed which
makes a solid assessment difficult. The present compound has a
calculated logKow of 8.23. Additionally, ACD labs was used to calculate
the logKow. It resulted in a logKow of 8.7. Due to these values, the
correlation of the logKow and the logBCF is uncertain and the QSAR
calculation of the regression-based estimation from EPISuite can only be
handled with caution.
T.E.S.T. package from the US EPA estimates BCF values using several
different advanced QSAR methodologies. The recommended model of the
T.E.S.T. package is the consensus method since it provides the most
accurate prediction. This model estimates the BCF by taking an average
of the predicted BCF values from the other applicable QSAR methods of
the package. For the present substance the consensus method averaged the
results from (1) the hierarchical clustering method, (2) the single
model method, (3) the group contribution method, (4) the FDA method and
(5) the nearest neighbor method. The resulting BCF value is 1418.78.
VEGA model was developed with several descriptors and is based on a
dataset of 473 compounds. It offers detailed information on the
applicability domain. In the present case, the calculation gave a BCF
value of 90. Since the Global AD Index was calculated to be 0.85 the
substance could be out of the Applicability Domain of the model.
summary, in a weight-of-evidence approach balancing the different QSAR
estimations and the experimental results the test substance is not
bioaccumulative according PBT-criteria.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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